When you cant move your fingers anymore because you are so cold, and your kids peel off the skin on their faces because they are bored, and frozen as they are they do not feel it anyway, I think you would not care about profanities like that.
I alos red some more comments. In practical use and with real-life consummation, it seems many people say they get over "one full season" with just 20l petroleum. Talking of campers in the main.
Note that you need special heater petroleuum for these ovens, lamp petroleum will ruin them. I dont know why, I just red it. Quality differences between different brands seem to be about how smelly the petroleums are.